AWS India SDET Interview: Rounds, Questions and Preparation

What the job involves

SDETs at global tech companies design and build automated test frameworks, tools, and suites that validate software at scale. They work closely with developers and product teams to ensure reliability, performance, and security across cloud services. Day to day involves writing code to test APIs, UIs, and distributed systems, analysing failures, and improving release quality.

Role and Technical Knowledge

1. 1

   What is the difference between a QA engineer and an SDET?

   Highlight that SDETs write production-level automation code, build frameworks, and contribute to test infrastructure, while QA engineers may focus more on manual testing and test case execution.

2. 2

   Explain the test automation pyramid and how you would apply it in a cloud service project.

   Describe the layers (unit, integration, UI) with emphasis on many unit tests, fewer integration tests, and minimal UI tests. Mention how cloud services benefit from API-level tests for scalability.

3. 3

   How would you test a REST API endpoint that returns a list of user orders?

   Cover status codes, response schema, authentication, pagination, error handling, and data validation. Mention tools like Postman or REST Assured and automating with assertions.

4. 4

   What are some key considerations when testing a microservices-based application on AWS?

   Discuss service isolation, contract testing, handling asynchronous communication, monitoring with CloudWatch, and testing for resilience and latency.

Practical Scenarios and Automation

1. 5

   You need to automate a login flow for a web application. How would you design the test script using Selenium?

   Mention using Page Object Model, handling waits, capturing screenshots on failure, and parameterizing credentials. Show awareness of cross-browser testing.

2. 6

   A test suite that used to pass is now failing intermittently in CI. How would you debug and fix it?

   Talk about identifying flakiness causes like timing issues, test data dependencies, or environment instability. Suggest adding retries, improving waits, and isolating tests.

3. 7

   How would you test a feature that uploads files to an S3 bucket and triggers a Lambda function?

   Outline unit tests for Lambda logic, integration tests for S3 events, and end-to-end tests verifying file processing. Mention mocking AWS services with tools like LocalStack.

4. 8

   Write a SQL query to find duplicate email addresses in a users table.

   Use GROUP BY and HAVING COUNT(*) > 1. Explain how you would validate the result and incorporate such checks into automated database tests.

Behavioural and Situational

1. 9

   Tell me about a time you found a critical bug late in a project. How did you handle it?

   Use STAR format: describe the situation, your action to mitigate, and the outcome. Emphasize communication, root cause analysis, and preventive measures.

2. 10

   Describe a situation where you had to learn a new testing tool or technology quickly.

   Show initiative and learning ability. Mention specific resources, practice, and how you applied it to a project or personal work.

3. 11

   How do you handle disagreements with a developer who thinks your test case is not valid?

   Focus on data-driven discussion, referencing requirements, and collaborating to understand the issue. Highlight respect and shared goal of quality.

4. 12

   Give an example of how you prioritized testing tasks when under a tight deadline.

   Discuss risk-based prioritization, focusing on critical paths, and communicating trade-offs. Mention using automation for regression to save time.

HR and Cultural Fit

1. 13

   Why do you want to work as an SDET at a global tech company like AWS?

   Connect personal interest in coding and quality with the scale and impact of cloud services. Mention desire to work on complex distributed systems.

2. 14

   Where do you see yourself in five years?

   Show ambition to grow technically, perhaps into a senior SDET or test architect role, while contributing to team and product success.

3. 15

   How do you stay updated with the latest testing tools and trends?

   Mention blogs, open-source communities, online courses, and hands-on experimentation. Give a recent example of something you learned.

4. 16

   Are you comfortable working in a fast-paced environment with changing priorities?

   Provide a brief example of adapting to change, staying organized, and maintaining focus on quality. Emphasize flexibility and positive attitude.